Coating device, coating method, and method for manufacturing photoconductor

ABSTRACT

A coating device includes: a coating liquid holding part that is provided with an upper opening portion and a lower opening portion and holds a coating liquid, and in which a cylindrical body penetrates the upper opening portion and the lower opening portion, and the cylindrical body is relatively moved to an upper side in an up-down direction, so that the coating liquid is applied to an outer peripheral surface of the cylindrical body; a container that accommodates the coating liquid that flows down; a circulation part that circulates the coating liquid in the container to the coating liquid holding part; and a receiving member that is disposed above a liquid level of the coating liquid in the container and receives the coating liquid flowing downward along the outer peripheral surface of the cylindrical body with an inclined surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 fromJapanese Patent Application No. 2021-202692 filed Dec. 14, 2021 and No.2021-080892 filed May 12, 2021.

BACKGROUND (i) Technical Field

The present invention relates to a coating device, a coating method, anda method for manufacturing a photoconductor.

(ii) Related Art

JP2002-045754 discloses a coating device that applies a coating liquidto the outer surface of a cylindrical substrate by immersing thecylindrical substrate in the coating liquid in a state where thecylindrical substrate is held with a cylinder axis being almostvertical, and pulling up the cylindrical substrate from the coatingliquid to the outside, the coating device including a coating tank whichaccommodates the coating liquid and in which the cylindrical substrateis immersed, and a coating liquid circulation mechanism which includesat least a defoaming tank that suppresses the occurrence of bubbles inthe coating liquid, and a circulation tank that circulates the coatingliquid to the coating tank, and in which the coating liquid is sent froma lower portion of the circulation tank to a lower portion of thecoating tank by a pressure pump, overflows from an upper edge portion ofthe coating tank, is returned to the defoaming tank, and is sent fromthe lower portion of the defoaming tank into the coating liquid in thecirculation tank, and the defoaming tank is provided with a coatingliquid supply port.

SUMMARY

Aspects of non-limiting embodiments of the present disclosure relate toa coating device, a coating method, and a method for manufacturing aphotoconductor, in which the occurrence of bubble defects in a coatedfilm on the outer peripheral surface of a cylindrical body is suppressedcompared to a case where a coating liquid flowing down along the outerperipheral surface of the cylindrical body falls to a liquid level ofthe coating liquid in a container.

Aspects of certain non-limiting embodiments of the present disclosureaddress the above advantages and/or other advantages not describedabove. However, aspects of the non-limiting embodiments are not requiredto address the advantages described above, and aspects of thenon-limiting embodiments of the present disclosure may not addressadvantages described above.

According to an aspect of the present disclosure, there is provided acoating device including: a coating liquid holding part that is providedwith an upper opening portion and a lower opening portion and holds acoating liquid, and in which a cylindrical body penetrates the upperopening portion and the lower opening portion, and the cylindrical bodyis relatively moved to an upper side in an up-down direction, so thatthe coating liquid is applied to an outer peripheral surface of thecylindrical body; a container that accommodates the coating liquid thatflows down; a circulation part that circulates the coating liquid in thecontainer to the coating liquid holding part; and a receiving memberthat is disposed above a liquid level of the coating liquid in thecontainer and receives the coating liquid flowing downward along theouter peripheral surface of the cylindrical body with an inclinedsurface.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiment(s) of the present invention will be described indetail based on the following figures, wherein:

FIG. 1 is a cross-sectional view showing an outline of an overallconfiguration of a coating device according to a first exemplaryembodiment;

FIG. 2 is a cross-sectional view showing a part of a coating liquidholding part that is used in the coating device according to the firstexemplary embodiment in an enlarged state;

FIG. 3 is a perspective view showing configurations of a receivingmember receiving a coating liquid and a container, which are used in thecoating device according to the first exemplary embodiment;

FIG. 4A is a configuration diagram showing a state before a cylindricalbody is inserted into the coating liquid holding part of the coatingdevice according to the first exemplary embodiment, FIG. 4B is aconfiguration diagram showing a state where the cylindrical body isinserted into the coating liquid holding part of the coating device andlowered, and FIG. 4C is a configuration diagram showing a state wherethe cylindrical body is being moved upward in an up-down direction withrespect to the coating liquid holding part;

FIG. 5A is a side view showing a part of the cylindrical body in which acoated film by a coating liquid is formed on an outer peripheral surfaceof the cylindrical body, and FIG. 5B is a sectional view taken alongline 5B-5B in FIG. 5A;

FIG. 6 is a side view showing the receiving member that is used in thecoating device according to the first exemplary embodiment in anenlarged state;

FIG. 7 is a side view showing a receiving member that is used in acoating device according to a second exemplary embodiment in an enlargedstate;

FIG. 8 is a side view showing a receiving member that is used in acoating device according to a third exemplary embodiment in an enlargedstate;

FIG. 9 is a side view showing a receiving member that is used in acoating device according to a fourth exemplary embodiment in an enlargedstate; and

FIG. 10 is a schematic perspective view showing a configuration of acontainer of a coating device according to a comparative example.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments for carrying out the technique of thepresent disclosure will be described. In the following description, thedirection indicated by an arrow UP appropriately shown in the drawingsis defined as the upper side in an up-down direction of a device.

First Exemplary Embodiment

Overall Configuration of Coating Device

In FIG. 1, an example of a coating device 10 according to a firstexemplary embodiment is shown in a cross-sectional view.

As shown in FIG. 1, the coating device 10 is a device for applying acoating liquid L to an outer peripheral surface 100A of a cylindricalbody 100. The coating device 10 includes a coating liquid holding part12 in which the coating liquid L is held, and a container 14 thataccommodates the coating liquid L flowing down from the coating liquidholding part 12 side. Further, the coating device 10 includes acirculation part 16 that circulates the coating liquid L in thecontainer 14 to the coating liquid holding part 12, and a receivingmember 18 that receives the coating liquid L flowing down along theouter peripheral surface 100A of the cylindrical body 100. The coatingdevice 10 includes a tubular housing 20. The coating liquid holding part12 is supported on the upper portion side in the up-down direction inthe housing 20. Further, the container 14 is provided at a lower portionin the up-down direction of the housing 20.

Cylindrical Body

The cylindrical body 100 is, for example, a cylindrical member made ofmetal or a member obtained by winding an endless belt-shaped member madeof metal around a cylindrical core material. The cylindrical member orthe endless belt-shaped member configuring the cylindrical body 100 is,for example, a photoconductor substrate or the like for anelectrophotography. Further, for example, in a case where thephotoconductor substrate for an electrophotography is used as thecylindrical body 100, a liquid containing a photosensitive material, orthe like, is used as the coating liquid L. In the present exemplaryembodiment, the coating liquid L is applied to the cylindrical member orthe endless belt-shaped member configuring the cylindrical body 100 bythe coating device 10. By using the liquid containing a photosensitivematerial as the coating liquid L, a photoconductor for anelectrophotography can be manufactured.

Housing

As shown in FIG. 1, the housing 20 is configured with a cylindricalmember, and is disposed such that an axial direction of the housing 20is in the up-down direction.

As an example, for example, the housing 20 includes a cylindricalportion 20A disposed along the up-down direction.

An upper wall portion 21B extending inward in a radial direction isprovided at the upper end portion of the cylindrical portion 20A, and acircular opening 21C is formed in the upper wall portion 21B. The innerdiameter of the opening 21C is larger than the outer diameter of thecylindrical body 100. A configuration is made such that the cylindricalbody 100 penetrates the opening 21C of the upper wall portion 21B in theaxial direction.

Coating Liquid Holding Part

As shown in FIGS. 1 and 2, the coating liquid holding part 12 has atubular shape and has a function of discharging the coating liquid Linward in the radial direction. In this way, the coating liquid L isapplied to the outer peripheral surface 100A of the cylindrical body 100that is inserted into the coating liquid holding part 12. The coatingliquid holding part 12 includes a case 24. The case 24 includes acylindrical portion 24A, an upper wall portion 24B bent inward in theradial direction from an upper end portion of the cylindrical portion24A, and a block portion 24C provided on the lower portion side of thecylindrical portion 24A.

An inflow port 24E into which the coating liquid L flows is provided atthe lower portion on one side in the radial direction of the cylindricalportion 24A.

An upper opening portion 25 having a circular shape is provided in theupper wall portion 24B (refer to FIG. 2). The inner diameter of theupper opening portion 25 is larger than the outer diameter of thecylindrical body 100. A configuration is made such that the cylindricalbody 100 penetrates the upper opening portion 25 of the upper wallportion 24B in the axial direction.

The block portion 24C includes a bottom wall portion 26A connected tothe lower end portion of the cylindrical portion 24A, and a tubularinner side wall portion 26B extending upward from an inner end portionin the radial direction of the bottom wall portion 26A. An inclinedportion 27 disposed to have an upward slope toward the inner side in theradial direction is formed on the upper portion side of the inner sidewall portion 26B. A lower opening portion 28 having a circular shape isprovided in the upper end portion of the inclined portion 27 of theinner side wall portion 26B. The inner diameter of the lower openingportion 28 is larger than the outer diameter of the cylindrical body100. Further, the inner diameter of the lower opening portion 28 issmaller than the inner diameter of the upper opening portion 25. Aconfiguration is made such that the cylindrical body 100 penetrates thelower opening portion 28 of the block portion 24C in the axialdirection.

The coating liquid holding part 12 is supported on the upper portionside in the up-down direction inside the housing 20 by a supportingportion (not shown).

The case 24 includes the cylindrical portion 24A, the upper wall portion24B, and the block portion 24C, so that the upper side of the blockportion 24C is open inward in the radial direction. An annular body 32is provided above the block portion 24C in the case 24. An installationsurface 30 on which the annular body 32 is movably disposed is providedat the upper portion of the block portion 24C. The installation surface30 has a planar shape and is disposed along the horizontal direction.

The annular body 32 is disposed in the open portion on the inner side inthe radial direction of the case 24. The inner diameter of the annularbody 32 is larger than the outer diameter of the cylindrical body 100.As an example, the inner diameter of the annular body 32 is smaller thanthe inner diameter of the lower opening portion 28. The inner peripheralsurface 32A side of the annular body 32 is exposed to a region throughwhich the cylindrical body 100 penetrates (refer to FIG. 2). Aconfiguration is made such that the cylindrical body 100 penetrates theinside of the annular body 32 in the axial direction. As an example, theannular body 32 is disposed in a state where the coating liquid L isinterposed between the annular body 32 and the installation surface 30.The annular body 32 is made to be movable (in the present exemplaryembodiment, slidable) relative to the installation surface 30. In thepresent exemplary embodiment, a driving unit that directly drives theannular body 32 is not provided, and the annular body 32 is made toautonomously slide relative to the installation surface 30.

As an example, an inclined surface 33A that is disposed on the upperportion side and has a downward slope from the upper opening portion 25side, and a straight portion 33B disposed straight along the up-downdirection from a lower end portion of the inclined surface 33A areprovided on the inner peripheral surface 32A of the annular body 32(refer to FIG. 2).

A flow path 34 through which the coating liquid L flows is providedbetween the cylindrical portion 24A and the block portion 24C andbetween the cylindrical portion 24A and the annular body 32 inside thecase 24. The end portion of the flow path 34 on the upstream side in aflow direction of the coating liquid L is connected to the inflow port24E (refer to FIG. 1). The coating liquid holding part 12 is providedwith a slit-shaped discharge portion 36 along the circumferentialdirection between the upper opening portion 25 of the upper wall portion24B and the annular body 32, and the coating liquid L is discharged fromthe discharge portion 36 (refer to FIG. 2). That is, the dischargeportion 36 faces the region of the coating liquid holding part 12,through which the cylindrical body 100 penetrates, and the coatingliquid L is discharged toward the cylindrical body 100 side. The coatingliquid L discharged from the discharge portion 36 overflows from theupper opening portion 25 toward the upper surface side of the upper wallportion 24B, and flows downward between the annular body 32 and theouter peripheral surface 100A of the cylindrical body 100.

In this state, the coating liquid L is applied to the outer peripheralsurface 100A of the cylindrical body 100 by moving the cylindrical body100 to the upper side in the up-down direction relative to the coatingliquid holding part 12 (refer to FIGS. 4B and 4C). In the coating liquidholding part 12, the coating liquid L flows between the outer peripheralsurface 100A of the cylindrical body 100 and the inner peripheralsurface 32A of the annular body 32, and the annular body 32 is movablerelative to the installation surface 30 by the pressure due to the flowof the coating liquid L. At this time, the annular body 32 is movablerelative to the installation surface 30 such that the gap between theouter peripheral surface 100A of the cylindrical body 100 and the innerperipheral surface 32A of the annular body 32 becomes uniform along thecircumferential direction.

In FIGS. 4A to 4C, an example of a method of applying the coating liquidL to the outer peripheral surface 100A of the cylindrical body 100 bythe coating liquid holding part 12 of the coating device 10 is shown. Asshown in FIG. 4A, the cylindrical body 100 is inserted along the axialdirection from the upper side of the coating liquid holding part 12, andthe cylindrical body 100 is moved downward (in a direction of an arrowA). As shown in FIG. 4B, the cylindrical body 100 is further lowered inthe direction of the arrow A, and the coating liquid L is supplied tothe coating liquid holding part 12 by the circulation part 16 (refer toFIG. 1), so that the coating liquid L is filled between the annular body32 of the coating liquid holding part 12 and the outer peripheralsurface 100A of the cylindrical body 100. Then, the cylindrical body 100reaches the lowermost portion, so that the upper end portion in theaxial direction of the cylindrical body 100 is disposed at a positionfacing the coating liquid holding part 12.

Thereafter, as shown in FIG. 4C, the cylindrical body 100 is movedupward (in a direction of an arrow B) with respect to the coating liquidholding part 12. At this time, the coating liquid L is discharged fromthe discharge portion 36 such that the coating liquid L overflows fromthe upper side. In this way, the coating liquid L flows out downwardfrom the lower opening portion 28, and the coating liquid L is appliedto the outer peripheral surface 100A of the cylindrical body 100 locatedabove the upper opening portion 25, so that a coated film 102 is formedon the outer peripheral surface 100A of the cylindrical body 100 (referto FIG. 5B). FIGS. 4A to 4C show an example of the method of applyingthe coating liquid L to the outer peripheral surface 100A of thecylindrical body 100, and the coating method can be changed.

As shown in FIG. 5A, in the process in which the coating liquid L isapplied to the outer peripheral surface 100A of the cylindrical body100, the coating liquid L applied to the outer peripheral surface 100Aof the cylindrical body 100 flows downward along the outer peripheralsurface 100A of the cylindrical body 100.

Further, as shown in FIG. 1, in the coating device 10, a wall portion 50is provided on the lower side of the coating liquid holding part 12inside the housing 20. An opening portion 50A through which thecylindrical body 100 penetrates is provided at the wall portion 50.Further, a hole portion 50B disposed at a position adjacent to the innerwall surface of the housing 20 is provided at the lower end portion inthe diagonal direction of the wall portion 50. In this way, the coatingliquid L flows down from the hole portion 50B of the wall portion 50along the inner wall surface of the housing 20, and the coating liquid Lis collected in the container 14.

Container

As shown in FIG. 1, the container 14 is connected to the lower endportion of the cylindrical portion 20A of the housing 20. The container14 includes a cylindrical portion 14A connected to the cylindricalportion 20A, and a recess portion 14B disposed at the lower portion ofthe cylindrical portion 14A and having a valley-shaped bottom surface.In the present exemplary embodiment, the bottom surface of the recessportion 14B has an inverted conical shape in which the inner diametergradually decreases toward the lower side.

The recess portion 14B has a bottom surface inclined to have a downwardslope from the cylindrical portion 14A side toward the central portionin the radial direction, and the central portion of the recess portion14B is the lowermost portion. The coating liquid L flowing down from thecoating liquid holding part 12 side is collected in the recess portion14B of the container 14. As an example, a liquid level L1 of the coatingliquid L is located on the upper portion side of the recess portion 14B.

Receiving Member

As shown in FIGS. 1 and 3, the receiving member 18 is provided in thecontainer 14. The receiving member 18 has a conical shape whose centralportion protrudes upward in the up-down direction. More specifically,the receiving member 18 includes an inclined surface 18A having anascending slope from the side of the recess portion 14B toward thecentral portion in the radial direction, and a top portion 18B formed atan upper end portion of the inclined surface 18A. The width of thelargest portion of the receiving member 18 in the direction orthogonalto the axial direction of the receiving member 18 is larger than theouter diameter of the cylindrical body 100. In this way, the receivingmember 18 is configured to receive the coating liquid L flowing downwardalong the outer peripheral surface 100A of the cylindrical body 100 withthe inclined surface 18A. In the present exemplary embodiment, theportion of the inclined surface 18A that receives the coating liquid Lis disposed above the liquid level L1 of the coating liquid L in thecontainer 14. Therefore, the coating liquid L flowing downward along theouter peripheral surface 100A of the cylindrical body 100 does notdirectly fall to the liquid level L1 of the coating liquid L.

In the present exemplary embodiment, as shown in FIG. 6, the inclinedsurface 18A has a straight line shape in a case of being viewed from thedirection orthogonal to the axial direction of the coating liquidholding part 12 (that is, in a case of being viewed in a side view). Asan example, the inclined surface 18A of the receiving member 18 issymmetrical in the right-left direction shown in FIG. 6. An angle θ1 ofthe inclined surface 18A with respect to the vertical direction ispreferably 10° or larger and 60° or smaller, more preferably 12° orlarger and 52° or smaller, and further preferably 15° or larger and 45°or smaller, for example. For example, the angle θl of the inclinedsurface 18A with respect to the vertical direction is set to 45°.

Circulation Part

As shown in FIG. 1, the circulation part 16 includes a supply pipe 60for supplying the coating liquid L in the container 14 to the coatingliquid holding part 12, and a pump 62 provided in the middle of thesupply pipe 60. The pump 62 transfers the coating liquid L in the supplypipe 60 from the container 14 side to the coating liquid holding part 12side.

An upstream-side end portion 60A in the flow direction of the coatingliquid L of the supply pipe 60 is connected to the lower portion of thecontainer 14. In the present exemplary embodiment, the upstream-side endportion 60A of the supply pipe 60 is connected to the central portionwhich is the lowermost portion of the recess portion 14B. Further, adownstream-side end portion 60B in the flow direction of the coatingliquid L of the supply pipe 60 penetrates the housing 20 and isconnected to the inflow port 24E of the coating liquid holding part 12.In this way, the coating liquid L flowing through the supply pipe 60 issupplied to the flow path 34 from the inflow port 24E. There is a casewhere the upstream side or the downstream side in the flow direction ofthe coating liquid L is simply referred to as the “upstream side” or the“downstream side” with the expression “the flow direction of the coatingliquid L” omitted.

Further, a filter 68 for removing foreign matter contained in thecoating liquid L is provided on the downstream side of the pump 62 inthe flow direction of the coating liquid L in the middle of the supplypipe 60.

In the coating device 10, the coating liquid L in the container 14 issupplied to the coating liquid holding part 12 through the supply pipe60 by driving the pump 62 of the circulation part 16. In the coatingliquid holding part 12, the coating liquid L is applied to the outerperipheral surface 100A of the cylindrical body 100, and the coatingliquid L flowing down along the outer peripheral surface 100A of thecylindrical body 100 falls to the inclined surface 18A of the receivingmember 18 and flows down on the inclined surface 18A to be collected inthe container 14. Then, the coating liquid L in the container 14 issupplied to the coating liquid holding part 12 through the supply pipe60. Therefore, the coating liquid L in the container 14 is circulated tothe coating liquid holding part 12 by the circulation part 16.

Operation and Effect

Next, the operation and effect of the present exemplary embodiment willbe described.

The coating device 10 includes the coating liquid holding part 12 whichis provided with the upper opening portion 25 and the lower openingportion 28 and holds the coating liquid L. In the coating liquid holdingpart 12, the cylindrical body 100 penetrates the upper opening portion25 and the lower opening portion 28, and the cylindrical body 100 isrelatively moved upward in the up-down direction, so that the coatingliquid L is applied to the outer peripheral surface 100A of thecylindrical body 100.

More specifically, as shown in FIG. 4A, the cylindrical body 100 isinserted in the direction of the arrow A from the upper side of thecoating liquid holding part 12. As shown in FIG. 4B, the cylindricalbody 100 is lowered in the direction of the arrow A, and the coatingliquid L is supplied to the coating liquid holding part 12 by thecirculation part 16 (refer to FIG. 1), so that the coating liquid L isfilled between the annular body 32 of the coating liquid holding part 12and the outer peripheral surface 100A of the cylindrical body 100. Then,the cylindrical body 100 reaches the lowermost portion.

Thereafter, as shown in FIG. 4C, the cylindrical body 100 is movedupward (in the direction of the arrow B) with respect to the coatingliquid holding part 12, and the coating liquid L is discharged from thedischarge portion 36 such that the coating liquid L overflows from theupper side. In this way, the coating liquid L flows out downward fromthe lower opening portion 28, and the coating liquid L is applied to theouter peripheral surface 100A of the cylindrical body 100 located abovethe upper opening portion 25. In this way, the coated film 102 is formedon the outer peripheral surface 100A of the cylindrical body 100 (referto FIG. 5B).

The coating device 10 is provided with the container 14 thataccommodates the coating liquid L flowing down from the coating liquidholding part 12 side, and the receiving member 18 that receives thecoating liquid L flowing downward along the outer peripheral surface100A of the cylindrical body 100 with the inclined surface 18A. Theportion of the inclined surface 18A of the receiving member 18 thatreceives the coating liquid L is disposed above the liquid level L1 ofthe coating liquid L in the container 14. In this way, the coatingliquid L flowing downward along the outer peripheral surface 100A of thecylindrical body 100 is received by the inclined surface 18A, and thecoating liquid L flows down along the inclined surface 18A, so that thecoating liquid L is collected in the container 14 (refer to FIG. 3).

Further, the coating device 10 includes the circulation part 16 thatcirculates the coating liquid L in the container 14 to the coatingliquid holding part 12. In the circulation part 16, the coating liquid Lin the container 14 is supplied to the coating liquid holding part 12through the supply pipe 60 by driving the pump 62.

In the coating device 10 described above, the coating liquid L flowingdownward along the outer peripheral surface 100A of the cylindrical body100 is received by the inclined surface 18A of the receiving member 18.Then, since the coating liquid L flowing down along the inclined surface18A merges with the liquid level L1 of the coating liquid L in thecontainer 14, the coating liquid L is difficult to foam. In this way, inthe coating device 10, the coating liquid L in the container 14 isdifficult to foam, compared to a case where the coating liquid flowingdown along the outer peripheral surface of the cylindrical body falls tothe liquid level of the coating liquid in the container. Therefore, whenthe coating liquid L in the container 14 is supplied to the coatingliquid holding part 12 through the supply pipe 60 by the circulationpart 16, inclusion of bubbles in the coating liquid L is reduced.Therefore, in the coating device 10, the occurrence of bubble defects inthe coated film 102 of the outer peripheral surface 100A of thecylindrical body 100 is suppressed compared to a case where the coatingliquid flowing down along the outer peripheral surface of thecylindrical body falls to the liquid level of the coating liquid in thecontainer.

In FIG. 10, a coating device 200 of a comparative example is shown. Asshown in FIG. 10, in the coating device 200, a container 202 thataccommodates the coating liquid L is provided at the lower part of thehousing 20. The container 202 includes a concave portion 202A formed inan inverted conical shape. More specifically, the concave portion 202Ais provided with an inclined surface 203 formed such that the innerdiameter thereof gradually decreases toward the lower portion side, andthe central portion is located at the lowest position. That is, theconcave portion 202A has a shape in which the inclined surface 203 isrecessed in a valley shape. A liquid level L2 of the coating liquid Laccumulated in the concave portion 202A is located on the upper portionside of the concave portion 202A. The container 202 is not provided withthe receiving member as in the first exemplary embodiment.

In the coating device 200, the coating liquid L that has flowed downalong the outer peripheral surface 100A of the cylindrical body 100falls to the liquid level L2 of the coating liquid L accumulated in thecontainer 202. That is, a configuration is made such that the coatingliquid L that has flowed down along the outer peripheral surface 100A ofthe cylindrical body 100 does not directly fall to the inclined surface203. At this time, the coating liquid L tends to foam due to the impactwhen the fallen droplets of the coating liquid L hit the liquid level L2of the coating liquid L. In this way, bubbles 210 are generated near theliquid level L2 of the coating liquid L. Therefore, when the coatingliquid L in the container 202 is supplied to the coating liquid holdingpart by the circulation part, there is a case where bubbles are includedin the coating liquid L.

In contrast, in the coating dvic 10 of the first exemplary embodiment,the coating liquid L flowing downward along the outer peripheral surface100A of the cylindrical body 100 is received by the inclined surface 18Aof the receiving member 18, and flows down on the inclined surface 18Ato be collected in the container 14. In this way, the impact when thecoating liquid L flowing down on the inclined surface 18A merges withthe coating liquid L in the container 14 is alleviated, and bubbles aredifficult to be generated in the coating liquid L in the container 14.Therefore, in the coating device 10, the occurrence of bubble defects inthe coated film 102 of the outer peripheral surface 100A of thecylindrical body 100 is suppressed compared to a case where the coatingliquid L flowing down along the outer peripheral surface 100A of thecylindrical body 100 falls to the liquid level L2 of the coating liquidL in the container 202.

Further, in the coating device 10, the inclined surface 18A has astraight linear shape in a case of being viewed from the directionorthogonal to the axial direction of the coating liquid holding part 12,and the angle θl of the inclined surface 18A with respect to thevertical direction is 10° or larger and 60° or smaller. Therefore, inthe coating device 10, foaming due to the impact when the coating liquidL is received by the receiving member 18 is suppressed compared to acase where the angle of the inclined surface with respect to thevertical direction is smaller than 10°. Further, foaming when thecoating liquid L received by the receiving member 18 merges with theliquid level L1 of the coating liquid L in the container 14 issuppressed compared to a case where the angle of the inclined surfacewith respect to the vertical direction is larger than 60°.

Further, in the coating device 10, the angle θl of the inclined surface18A with respect to the vertical direction is 15° or larger and 45° orsmaller. Therefore, in the coating device 10, foaming due to the impactwhen the coating liquid L is received by the receiving member 18 issuppressed compared to a case where the angle of the inclined surfacewith respect to the vertical direction is smaller than 15°. Further,foaming when the coating liquid L received by the receiving member 18merges with the liquid level L1 of the coating liquid L in the container14 is suppressed compared to a case where the angle of the inclinedsurface with respect to the vertical direction is larger than 45°.

Further, in the coating device 10, the inclined surface 18A has aconical shape whose central portion protrudes in a case of being viewedin a side view.

Therefore, in the coating device 10, the coating liquid L falling fromthe outer peripheral surface 100A of the cylindrical body 100 isdifficult to come into contact with the liquid level L1 of the coatingliquid L in the container 14, compared to a case where the inclinedsurface has a shape recessed in a valley shape.

Further, a coating method of applying a coating liquid by using thecoating device 10 includes moving the cylindrical body 100 upward in theup-down direction relative to the coating liquid holding part 12 andapplying the coating liquid L from the coating liquid holding part 12 tothe outer peripheral surface 100A of the cylindrical body 100. Further,the coating method includes receiving the coating liquid L flowingdownward along the outer peripheral surface 100A of the cylindrical body100 with the inclined surface 18A of the receiving member 18 above theliquid level L1 of the coating liquid L in the container 14 andaccommodating the coating liquid L in the container 14. Further, thecoating method includes circulating the coating liquid L in thecontainer 14 to the coating liquid holding part 12 by the circulationpart 16. Therefore, in the coating method, the occurrence of bubbledefects in the coated film 102 on the outer peripheral surface 100A ofthe cylindrical body 100 is suppressed compared to a case where thecoating liquid flowing down along the outer peripheral surface of thecylindrical body falls to the liquid level of the coating liquid in thecontainer.

Further, in the coating method of applying the coating liquid by usingthe coating device 10, the cylindrical body 100 is a cylindrical memberor a member obtained by winding an endless belt-shaped member around acylindrical core material. Therefore, in the coating method, theoccurrence of bubble defects in the coated film 102 of the outerperipheral surface 100A of the cylindrical member or the endlessbelt-shaped member is suppressed compared to a case where the coatingliquid flowing down along the outer peripheral surface of thecylindrical body falls to the liquid level of the coating liquid in thecontainer.

Further, in a method for manufacturing a photoconductor by using thecoating method described above, the cylindrical body 100 is acylindrical member made of metal or a member obtained by winding anendless belt-shaped member made of metal around a cylindrical corematerial, and the coating liquid L contains a photosensitive material.Therefore, in the method for manufacturing a photoconductor, theoccurrence of bubble defects in the coated film 102 of the outerperipheral surface 100A of the photoconductor is suppressed compared toa case where the coating liquid flowing down along the outer peripheralsurface of the cylindrical body falls to the liquid level of the coatingliquid in the container.

Second Exemplary Embodiment

Next, a coating device 120 of a second exemplary embodiment will bedescribed using FIG. 7. The identical components to the configurationsof the first exemplary embodiment described above will be denoted theidentical reference numerals and the description thereof will beomitted.

As shown in FIG. 7, the coating device 120 includes a receiving member122 instead of the receiving member 18 of the coating device 10 of thefirst exemplary embodiment. The receiving member 122 has a flat plateshape, and has, on the upper surface thereof, an inclined surface 122Athat intersects the vertical direction. The inclined surface 122A isinclined to have a downward slope in one direction intersecting thevertical direction. In a state where the receiving member 122 isdisposed, the width of the receiving member 122 in the directionorthogonal to the vertical direction is larger than the outer diameterof the cylindrical body 100. In this way, the receiving member 122 isconfigured to receive the coating liquid L flowing downward along theouter peripheral surface 100A of the cylindrical body 100 with theinclined surface 122A.

An angle θ2 of the inclined surface 122A with respect to the verticaldirection is preferably 10° or larger and 60° or smaller, morepreferably 12° or larger and 52° or smaller, and further preferably 15°or larger and 45° or smaller, for example. For example, the angle θ2 ofthe inclined surface 122A with respect to the vertical direction is setto 45°. Other configurations of the coating device 120 are the same asthe configurations of the coating device 10 of the first exemplaryembodiment.

In the coating device 120 described above, the same operation and effectcan be obtained with the same configuration as the coating device 10 ofthe first exemplary embodiment.

Further, in the coating device 120, the inclined surface 122A isinclined to have a downward slope in one direction intersecting thevertical direction. Therefore, in the coating device 120, the structureof the receiving member 122 becomes simple, compared to a case where theinclined surface is inclined in a plurality of directions intersectingthe vertical direction.

Third Exemplary Embodiment

Next, a coating device 130 of a third exemplary embodiment will bedescribed using FIG. 8. The identical components to the configurationsof the first and second exemplary embodiments described above will bedenoted the identical reference numerals and the description thereofwill be omitted.

As shown in FIG. 8, the coating device 130 includes a receiving member132 instead of the receiving member 18 of the coating device 10 of thefirst exemplary embodiment. The receiving member 132 is a curvedplate-shaped body and has an inclined surface 132A on the upper surfacethereof. The inclined surface 132A is an example of a curved surface. Inthe present exemplary embodiment, the inclined surface 132A is a curvedsurface formed to be convex upward. In a state where the receivingmember 132 is disposed, the width of the receiving member 132 in thedirection orthogonal to the vertical direction is larger than the outerdiameter of the cylindrical body 100. In this way, the receiving member132 is configured to receive the coating liquid L flowing downward alongthe outer peripheral surface 100A of the cylindrical body 100 with theinclined surface 132A.

For example, a virtual tangent surface 135 at an intersection point 135Aof the inclined surface 132A with one extension line 134A extendingdownward along the outer peripheral surface 100A of the cylindrical body100 is depicted. Further, a virtual tangent surface 136 at anintersection point 136A of the inclined surface 132A with one extensionline 134B extending downward along the outer peripheral surface 100A ofthe cylindrical body 100 is depicted. The tangent surfaces 135 and 136shown in FIG. 8 are synonymous with tangent lines in the cross section.At this time, an angle θ31 between the tangent surface 135 and thevertical direction and an angle θ32 between the tangent surface 136 andthe vertical direction are preferably 10° or larger and 60° or smaller,more preferably 12° or larger and 52° or smaller, and further preferably15° or larger and 45° or smaller, for example. For example, the angleθ31 between the tangent surface 135 and the vertical direction is set to60°, and the angle θ32 between the tangent surface 136 and the verticaldirection is set to 30°. Other configurations of the coating device 130are the same as the configurations of the coating device 10 of the firstexemplary embodiment.

In the coating device 130 described above, the same operation and effectcan be obtained with the same configuration as the coating device 10 ofthe first exemplary embodiment.

Further, in the coating device 130, the angle θ31 between the tangentsurface 135 and the vertical direction and the angle θ32 between thetangent surface 136 and the vertical direction are 10° or larger and 60°or smaller. Therefore, in the coating device 130, foaming due to theimpact when the coating liquid L is received by the receiving member 132is suppressed compared to a case where the angle θ31 between the tangentsurface 135 and the vertical direction and the angle θ32 between thetangent surface 136 and the vertical direction are smaller than 10°.Further, foaming when the coating liquid L received by the receivingmember 132 merges with the liquid level L1 of the coating liquid L inthe container 14 is suppressed compared to a case where the angle θ31between the tangent surface 135 and the vertical direction and the angleθ32 between the tangent surface 136 and the vertical direction arelarger than 60°.

Further, although not shown in the drawing, in the coating device 130,the angle θ31 between the tangent surface 135 and the vertical directionand the angle θ32 between the tangent surface 136 and the verticaldirection is preferably 15° or larger and 45° or smaller, for example.In this case, in the coating device 130, foaming due to the impact whenthe coating liquid L is received by the receiving member 132 issuppressed compared to a case where the angle θ31 between the tangentsurface 135 and the vertical direction and the angle θ32 between thetangent surface 136 and the vertical direction are smaller than 15°.Further, foaming when the coating liquid L received by the receivingmember 132 merges with the liquid level L1 of the coating liquid L inthe container 14 is suppressed compared to a case where the angle θ31between the tangent surface 135 and the vertical direction and the angleθ32 between the tangent surface 136 and the vertical direction arelarger than 45°.

Fourth Exemplary Embodiment

Next, a coating device 140 of a fourth exemplary embodiment will bedescribed using FIG. 9. The identical components to the configurationsof the first to third exemplary embodiments described above will bedenoted the identical reference numerals and the description thereofwill be omitted.

As shown in FIG. 9, the coating device 140 includes a receiving member142 instead of the receiving member 18 of the coating device 10 of thefirst exemplary embodiment. The receiving member 142 includes aninclined surface 142A that is a curved surface portion whose centralportion projects in a mountain shape in a case of being viewed in a sideview orthogonal to the axial direction of the container 14. Thereceiving member 142 is provided with an apex 142B, which is theuppermost portion of the curved surface portion, at the central portionof the inclined surface 142A.

The width of the receiving member 142 in the direction orthogonal to thevertical direction is larger than the outer diameter of the cylindricalbody 100. In this way, the receiving member 142 is configured to receivethe coating liquid L flowing downward along the outer peripheral surface100A of the cylindrical body 100 with the inclined surface 142A.

For example, a virtual tangent surface 145 at an intersection point 145Aof the inclined surface 142A with an extension line 144 extendingdownward along the outer peripheral surface 100A of the cylindrical body100 is depicted. The tangent surface 145 is synonymous with a tangentline in the cross section. At this time, an angle between the tangentsurface 145 and the vertical direction is preferably 10° or larger and60° or smaller, more preferably 12° or larger and 52° or smaller, andfurther preferably 15° or larger and 45° or smaller, for example. Forexample, the angle θ4 between the tangent surface 145 and the verticaldirection is set to 20°. Other configurations of the coating device 140are the same as the configurations of the coating device 10 of the firstexemplary embodiment.

In the coating device 140 described above, the same operation and effectcan be obtained with the same configuration as the coating device 10 ofthe first exemplary embodiment.

Further, in the coating device 140, the inclined surface 142A is acurved surface portion whose central portion protrudes in a mountainshape in a case of being viewed in a side view. Therefore, in thecoating device 140, the coating liquid L falling from the outerperipheral surface 100A of the cylindrical body 100 is difficult to comeinto contact with the liquid level L1 of the coating liquid L in thecontainer 14, compared to a case where the inclined surface has a shaperecessed in a valley shape.

Further, in the coating device 140, the angle θ4 between the tangentsurface 145 and the vertical direction is 10° or larger and 60° orsmaller. Therefore, in the coating device 140, foaming due to the impactwhen the coating liquid L is received by the receiving member 142 issuppressed compared to a case where the angle θ4 between the tangentsurface 145 and the vertical direction is smaller than 10°. Further,foaming when the coating liquid L received by the receiving member 142merges with the liquid level L1 of the coating liquid L in the container14 is suppressed compared to a case where the angle between the tangentsurface 145 and the vertical direction is larger than 60°.

Further, in the coating device 140, the angle θ4 between the tangentsurface 145 and the vertical direction is 15° or larger and 45° orsmaller. In the coating device 140, foaming due to the impact when thecoating liquid L is Received by the receiving member 142 is suppressedcompared to a case where the angle θ4 between the tangent surface 145and the vertical direction is smaller than 15°. Further, foaming whenthe coating liquid L received by the receiving member 142 merges withthe liquid level L1 of the coating liquid L in the container 14 issuppressed compared to a case where the angle θ4 between the tangentsurface 145 and the vertical direction is larger than 45°.

Supplementary Description

In the first to fourth exemplary embodiments, the shape of the receivingmember can be changed as long as the shape is a shape in which thecoating liquid L that has fallen from the outer peripheral surface 100Aof the cylindrical body 100 is received by the inclined surface of thereceiving member above the liquid level of the coating liquid in thecontainer.

In the first to fourth exemplary embodiments, the configuration of eachmember of the coating liquid holding part 12 can be changed as long asthe configuration is a configuration capable of applying the coatingliquid L to the outer peripheral surface 100A of the cylindrical body100. Further, the shape of the annular body 32 can also be changed.

Although the present invention has been described in detail based on theexemplary embodiments, the present invention is not limited to suchexemplary embodiments, and it will be apparent to the persons skilled inthe art that various other embodiments are possible within the scope ofthe present invention.

EXAMPLES

Hereinafter, the coating device and the coating method of the presentdisclosure will be more specifically described by way of examples.However, the coating device and the coating method of the presentdisclosure are not limited to the following examples as long as the gistis not exceeded.

Example 1

Preparation of Coating Liquid

The coating liquid L for forming a charge transport layer is prepared bydissolving 2.6 parts by mass of benzidine compound represented byFormula (CT-1) shown by Chemical formula 1 below and 3 parts by mass ofpolymer compound (viscosity average molecular weight: 40,000) having arepeating unit represented by Formula (B-1) shown by Chemical formula 2below in 25 parts by mass of tetrahydrofuran. The coating liquid L is aliquid containing a photosensitive material for manufacturing aphotoconductor for an electrophotography.

Application

Application of the coating liquid L to the cylindrical body 100 isperformed using an aluminum pipe having ϕ84 ×340 mm as the cylindricalbody 100 and using the coating device 10 shown in FIG. 1 and the coatingliquid L described above. As the receiving member (a liquid receivingmember in Table 1) installed in the container 14 of the coating device10, the receiving member 18 shown in FIG. 1 is used. The angle of theinclined surface 18A of the receiving member 18 with respect to thevertical direction is set to 45°.

The inner diameter of the annular body 32 of the coating device 10 is85.0 mm. The coating liquid L is constantly circulated and supplied tothe coating liquid holding part 12 at 0.4 L/min and to the cylindricalbody 100 below the upper opening portion 25 at 0.4 L/min. Whileconstantly circulating and supplying the coating liquid L under suchconditions, the upper portion of the inner surface of the cylindricalbody 100 is gripped by a grip portion (not shown) and the cylindricalbody 100 is lowered from the upper side in the vertical direction. Atthis time, the cylindrical body 100 is caused to penetrate the upperopening portion 25 provided in the coating liquid holding part 12 at aconstant speed of 500 ram/min from the upper side in the verticaldirection toward the lower side. Until the cylindrical body 100 reachesthe lowest point, the coating liquid L filled the coating liquid holdingpart 12 and is in an overflow state.

Next, the cylindrical body 100 is pulled up at a constant speed of 150mm/min to form the coated film 102 by the coating liquid L on the outerperipheral surface 100A of the cylindrical body 100. During moving upand down of the cylindrical body 100 through the upper opening portion25, the coating liquid L discharged from the slit-shaped dischargeportion 36 provided in the upper opening portion is applied to theentire periphery of the outer peripheral surface 100A of the cylindricalbody 100 below the upper opening portion 25, and the coating liquid Lflowed down from the outer peripheral surface 100A of the cylindricalbody 100 due to gravity. A sample in which the coating liquid L isapplied to the cylindrical body 100 (the coated film 102 is formed onthe outer peripheral surface 100A of the cylindrical body 100) is driedwith hot air at 135° C. for 40 minutes.

The bubble defects in the coated film 102 of the cylindrical body 100,which is an evaluation item, are observed with a microscope image, anddecided based on the criteria of A to C below according to the number ofbubble defects having a size of 100 μm or larger per piece.

A: No bubble defect occurs.

B: Two or less bubble defects occur.

C: Three or more bubble defects occur.

Examples 2 to 5

Application of the coating liquid L is performed while changing theangle of the inclined surface 18A of the receiving member 18 (the liquidreceiving member) with respect to the vertical direction, as in Examples2 to 5 shown in Table 1.

Comparative Examples 1 to 3

Application of the coating liquid L is performed while changing theangle of the inclined surface 18A of the receiving member 18 (the liquidreceiving member) with respect to the vertical direction, as inComparative Examples 1 and 2 shown in Table 1. Further, in ComparativeExample 3, application of the coating liquid L is performed withoutproviding a receiving member in the container 14. The results ofevaluating the occurrence status of bubble defects in the coated film102 of the cylindrical body 100 are shown in Table 1.

TABLE 1 Angle of inclined surface of liquid receiving member withrespect to vertical direction Bubble defects Example 1 10 B Example 2 15A Example 3 30 A Example 4 45 A Example 5 60 B Comparative Example 1 5 CComparative Example 2 75 C Comparative Example 3 Without liquid Creceiving member

As shown in Table 1, in Examples 2 to 4, it is confirmed that no bubbledefect occurred in the coated film 102 of the cylindrical body 100.Further, in Examples 1 and 5, it is confirmed that the number of bubbledefects occurred in the coated film 102 of the cylindrical body 100 istwo or less.

In contrast, in Comparative Examples 1 to 3, it is confirmed that thenumber of bubble defects occurred in the coated film 102 of thecylindrical body 100 is three or more. In Comparative Example 2, sincethe angle of the inclined surface of the receiving member 18 withrespect to the vertical direction is large (the inclination of theinclined surface with respect to the horizontal direction is gentle), itis considered that foaming is generated due to the impact when thefalling coating liquid L collides with the receiving member. On theother hand, in a case where the angle of the inclined surface of thereceiving member 18 with respect to the vertical direction is small (theinclination of the inclined surface with respect to the horizontaldirection is steep) as in Comparative Example 1, since the fallingcoating liquid L merges with the liquid level without being sufficientlydecelerated, it is considered that foaming cannot be sufficientlyprevented.

The foregoing description of the exemplary embodiments of the presentinvention has been provided for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to practitioners skilled in the art. Theembodiments are chosen and described in order to best explain theprinciples of the invention and its practical applications, therebyenabling others skilled in the art to understand the invention forvarious embodiments and with the various modifications as are suited tothe particular use contemplated. It is intended that the scope of theinvention be defined by the following claims and their equivalents.

What is claimed is:
 1. A coating device comprising: a coating liquidholding part that is provided with an upper opening portion and a loweropening portion and holds a coating liquid, and in which a cylindricalbody penetrates the upper opening portion and the lower opening portion,and the cylindrical body is relatively moved to an upper side in anup-down direction, so that the coating liquid is applied to an outerperipheral surface of the cylindrical body; a container thataccommodates the coating liquid that flows down; a circulation part thatcirculates the coating liquid in the container to the coating liquidholding part; and a receiving member that is disposed above a liquidlevel of the coating liquid in the container and receives the coatingliquid flowing downward along the outer peripheral surface of thecylindrical body with an inclined surface.
 2. The coating deviceaccording to claim 1, wherein the inclined surface has a flat plateshape or a straight line shape in a case of being viewed from adirection orthogonal to an axial direction of the coating liquid holdingpart, and an angle of the inclined surface with respect to a verticaldirection is 10° or larger and 60° or smaller.
 3. The coating deviceaccording to claim 2, wherein the angle of the inclined surface withrespect to the vertical direction is 15° or larger and 45° or smaller.4. The coating device according to claim 2, wherein the inclined surfaceis inclined to have a downward slope in one direction intersecting thevertical direction.
 5. The coating device according to claim 1, whereinthe inclined surface is a curved surface, and an angle between a tangentsurface at an intersection point of the curved surface with an extensionline extending downward along the outer peripheral surface of thecylindrical body and a vertical direction is 10° or larger and 60° orsmaller.
 6. The coating device according to claim 5, wherein the anglebetween the tangent surface at the intersection point of the curvedsurface with the extension line extending downward along the outerperipheral surface of the cylindrical body and the vertical direction is15° or larger and 45° or smaller.
 7. The coating device according toclaim 6, wherein the inclined surface is inclined to have a downwardslope in one direction intersecting the vertical direction.
 8. Thecoating device according to claim 2, wherein the inclined surface has aconical shape whose central portion protrudes in a case of being viewedin a side view.
 9. The coating device according to claim 3, wherein theinclined surface has a conical shape whose central portion protrudes ina case of being viewed in a side view.
 10. The coating device accordingto claim 1, wherein the inclined surface is a curved surface portionwhose central portion protrudes in a mountain shape in a case of beingviewed in a side view.
 11. The coating device according to claim 10,wherein an angle between a tangent surface at an intersection point ofthe inclined surface with an extension line extending downward along theouter peripheral surface of the cylindrical body and a verticaldirection is 10° or larger and 60° or smaller.
 12. A coating method ofapplying a coating liquid by using the coating device according to claim1, the coating method comprising: moving the cylindrical body upward inan up-down direction relative to the coating liquid holding part andapplying the coating liquid from the coating liquid holding part to theouter peripheral surface of the cylindrical body; receiving the coatingliquid flowing downward along the outer peripheral surface of thecylindrical body with the inclined surface of the receiving member abovea liquid level of the coating liquid in the container and accommodatingthe coating liquid in the container; and circulating the coating liquidin the container to the coating liquid holding part by the circulationpart.
 13. The coating method according to claim 12, wherein thecylindrical body is a cylindrical member or a member obtained by windingan endless belt-shaped member around a cylindrical core material.
 14. Amethod for manufacturing a photoconductor comprising using the coatingmethod according to claim 12, wherein the cylindrical body is acylindrical member made of metal or a member obtained by winding anendless belt-shaped member made of metal around a cylindrical corematerial, and the coating liquid contains a photosensitive material. 15.The coating method according to claim 12, wherein the inclined surfacehas a flat plate shape or a straight line shape in a case of beingviewed from a direction orthogonal to an axial direction of the coatingliquid holding part, and an angle of the inclined surface with respectto a vertical direction is 10° or larger and 60° or smaller.
 16. Thecoating method according to claim 15, wherein the angle of the inclinedsurface with respect to the vertical direction is 15° or larger and 45°or smaller.
 17. The coating method according to claim 12, wherein theinclined surface is a curved surface, and an angle between a tangentsurface at an intersection point of the curved surface with an extensionline extending downward along the outer peripheral surface of thecylindrical body and a vertical direction is 10° or larger and 60° orsmaller.
 18. The coating method according to claim 17, wherein the anglebetween the tangent surface at the intersection point of the curvedsurface with the extension line extending downward along an outerperipheral surface of the cylindrical body and the vertical direction is15° or larger and 45° or smaller.